The direction dependant wavelength selective transmission mechanism in poly (methyl
methacrylate)(PMMA) rods doped with C 540 dye and C 540:Rh.B dye mixture as a combination has been
investigated. When a polished slice of pure C 540 doped polymer rod was used side by side with a C540:Rh B
doped rod with acceptor concentration [A] = 7x10-4 m/l , we could notice more than 100% change in the
transmitted intensity along opposite directions at the C 540, Rh B emission and the excitation wavelengths . A
blue high bright LED emitting at a peak wavelength 465nm was used as the excitation source.